Merged concurrent changes.

Makefile.am

configure.ac

src/lib-sieve/Makefile.am

src/lib-sieve/plugins/environment/ext-environment-common.c

src/lib-sieve/plugins/environment/ext-environment-common.h

src/lib-sieve/plugins/environment/ext-environment.c

src/lib-sieve/plugins/environment/sieve-ext-environment.h

src/lib-sieve/plugins/environment/tst-environment.c

src/lib-sieve/plugins/variables/ext-variables-common.c

src/lib-sieve/plugins/variables/ext-variables-dump.c

src/lib-sieve/plugins/variables/ext-variables-namespaces.c

src/lib-sieve/plugins/variables/ext-variables-operands.c

src/lib-sieve/plugins/vnd.dovecot/Makefile.am

src/lib-sieve/plugins/vnd.dovecot/environment/Makefile.am

...gins/vnd.dovecot/environment/ext-vnd-environment-common.h

...ugins/vnd.dovecot/environment/ext-vnd-environment-items.c

...s/vnd.dovecot/environment/ext-vnd-environment-variables.c

...eve/plugins/vnd.dovecot/environment/ext-vnd-environment.c

src/lib-sieve/sieve-code.c

src/lib-sieve/sieve-extensions.c